package net.nchelluri.projectEuler.problems.p11to20;

public class Problem11 {
	public static void main(String[] args) {
		String input = "08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08\n"
				+ "49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00\n"
				+ "81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65\n"
				+ "52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91\n"
				+ "22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80\n"
				+ "24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50\n"
				+ "32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70\n"
				+ "67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21\n"
				+ "24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72\n"
				+ "21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95\n"
				+ "78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92\n"
				+ "16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57\n"
				+ "86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58\n"
				+ "19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40\n"
				+ "04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66\n"
				+ "88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69\n"
				+ "04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36\n"
				+ "20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16\n"
				+ "20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54\n"
				+ "01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48\n";

		String[] lines = input.split("\n");
		int dim = lines.length;
		int[][] grid = new int[dim][dim];
		for (int i = 0; i < dim; i++) {
			String line = lines[i];
			String[] entries = line.split(" ");
			for (int j = 0; j < dim; j++) {
				grid[i][j] = Integer.valueOf(entries[j]);
			}
		}

		int max = 0;
		for (int i = 0; i < grid.length; i++) {
			for (int j = 0; j < grid.length; j++) {
				int possible = findMaxProductInvolving(grid, i, j);
				max = max(max, possible);
			}
		}
		System.out.println(max);
	}

	private static int findMaxProductInvolving(int[][] grid, int i, int j) {
		int max = 0;

		max = max(max, findUp(grid, i, j));
		max = max(max, findDown(grid, i, j));
		max = max(max, findLeft(grid, i, j));
		max = max(max, findRight(grid, i, j));
		max = max(max, findDiagonallyUpLeft(grid, i, j));
		max = max(max, findDiagonallyDownRight(grid, i, j));
		max = max(max, findDiagonallyUpRight(grid, i, j));
		max = max(max, findDiagonallyDownLeft(grid, i, j));

		return max;
	}

	private static int findDiagonallyDownLeft(int[][] grid, int i, int j) {
		if (i - 3 < 0 || j + 3 >= grid.length) {
			return 0;
		}

		return grid[i][j] * grid[i - 1][j + 1] * grid[i - 2][j + 2]
				* grid[i - 3][j + 3];
	}

	private static int findDiagonallyUpRight(int[][] grid, int i, int j) {
		if (i + 3 >= grid.length || j - 3 < 0) {
			return 0;
		}

		return grid[i][j] * grid[i + 1][j - 1] * grid[i + 2][j - 2]
				* grid[i + 3][j - 3];
	}

	private static int findDiagonallyDownRight(int[][] grid, int i, int j) {
		if (i + 3 >= grid.length || j + 3 >= grid.length) {
			return 0;
		}

		return grid[i][j] * grid[i + 1][j + 1] * grid[i + 2][j + 2]
				* grid[i + 3][j + 3];
	}

	private static int findDiagonallyUpLeft(int[][] grid, int i, int j) {
		if (i - 3 < 0 || j - 3 < 0) {
			return 0;
		}

		return grid[i][j] * grid[i - 1][j - 1] * grid[i - 2][j - 2]
				* grid[j - 3][i - 3];
	}

	private static int findRight(int[][] grid, int i, int j) {
		if (i + 3 >= grid.length) {
			return 0;
		}

		return grid[i][j] * grid[i + 1][j] * grid[i + 2][j] * grid[i + 3][j];
	}

	private static int findLeft(int[][] grid, int i, int j) {
		if (i - 3 < 0) {
			return 0;
		}

		return grid[i][j] * grid[i - 1][j] * grid[i - 2][j] * grid[i - 3][j];
	}

	private static int findDown(int[][] grid, int i, int j) {
		if (j + 3 >= grid.length) {
			return 0;
		}

		return grid[i][j] * grid[i][j + 1] * grid[i][j + 2] * grid[i][j + 3];
	}

	private static int findUp(int[][] grid, int i, int j) {
		if (j - 3 < 0) {
			return 0;
		}

		return grid[i][j] * grid[i][j - 1] * grid[i][j - 2] * grid[i][j - 3];
	}

	private static int max(int x, int y) {
		return x > y ? x : y;
	}
}
